Old Dogs Can Learn to Like New Tricks: One Instructor\u27s Change in Attitude to Online Instruction from 2009-2017

This qualitative case study examined a veteran instructor\u27s change in attitude about university online instruction. After a short review of the literature and explanation of the project, researchers conducted a content analysis of an instructor\u27s annual self-reports about his online teaching of a graduate course in the social sciences. The self-reports were written between 2009 and 2017. The researchers also examined students\u27 end-of-semester evaluation scores about the course and instructor. Results suggest that the teacher began online teaching with a mixed attitude. After four years of teachin ghte online course (delivered once each spring) the instructor reported more about content issues and less about online delivery. In the final the period (2016-17) the researchers found that the instructor was invested fully in online delivery. Although the study is not generalizable, its results suggest that instructors who stay with an online system over an extended period of time may gain more confidence in the efficacy on online delivery. The findings complement previous findings in the literature about faculty attitudes toward technology use in instruction

Education Interrupted: The Growing Use of Suspensions in New York City's Public Schools

The New York Civil Liberties Union analyzed 10 years of discipline data from New York City schools, and found that:*The total number of suspensions in New York City grew at an alarming rate over the last decade: One out of every 14 students was suspended in 2008-2009; in 1999-2000 it was one in 25. In 2008-2009, this added up to more than 73,000 suspensions.*Students with disabilities are four times more likely to be suspended than students without disabilities.*Black students, who comprise 33 percent of the student body, served 53 percent of suspensions over the past 10 years. *Black students with disabilities represent more than 50 percent of suspended students with disabilities.*Black students also served longer suspensions on average and were more likely to be suspended for subjective misconduct, like profanity and insubordination.*Suspensions are becoming longer: More than 20 percent of suspensions lasted more than one week in 2008-2009, compared to 14 percent in 1999-2000. The average length of a long-term suspension is five weeks (25 school days).*Between 2001 and 2010, the number of infractions listed in the schools' Discipline Code increased by 49 percent. During that same period, the number of zero tolerance infractions, which mandate a suspension regardless of the individual facts of the incident, increased by 200 percent.*Thirty percent of suspensions occur during March and June of each school year

Differentiating the EdD and the PhD in Higher Education: A Survey of Characteristics and Trends

Purpose: Higher education, as a field of study, is one of the few programmatic areas that offer two doctoral degrees: The Doctor of Education (EdD) and the Doctor of Philosophy (PhD). In the United States, the two degrees are often conflated. Conversations, to this point, have done more to contribute to the theoretical debate than to operationally distinguish between the two degree paths. Method: The current study analyzed data collected from a review of the 188 doctoral programs at 145 institutions listed with the Association for the Study of Higher Education (ASHE). Results: Results suggest that while there is a shift toward operational differences between the EdD and the PhD in higher education, the similarities in entrance requirements, formats, and research expectations, to list a few, suggest that the EdD and PhD still require further refinement to reach the theoretical clarity common in many conversations about the education doctorate

Generation of a short fibre biocomposite representative volume element

One of the greatest challenge in working with natural fibre composites is the large variation in mechanical properties that result from the geometric inconsistency amongst fibres. Traditional design tools and models are unable to accurately incorporate this non-homogeneity to predict the resulting local behaviour of biocomposite materials. The following paper presents a methodology to generate a representative volume element (RVE) to simulate the material microstructure of short fibre composites, with the intent of modelling the popular class of short fibre biocomposites materials. The capabilities of a range of particle packing algorithms used in literature are compared in terms of the maximum volume fraction they have been able to achieve and for what fibre length to diameter aspect ratio. The methodology is able to account for the characteristics of fibre geometry samples, according to their probability density functions (PDFs). The RVE generation strategy imposes periodic boundary conditions and fibres are declared invalid if an intersection between fibres is detected. The effect of different PDFs on the resulting RVE are discussed. An RVE populated with data following a Weibull distribution is compared to that from normally distributed data with an equal mean but varied standard deviations. Using a Weibull distribution to simulate the characteristics of an RVE requires a significantly higher number of fibres than any comparable normal distribution, due to the skewness of the data towards large values at low probabilities. The highest volume fraction achieved was 40% for an RVE containing fibres with lengths distributed according to a Weibull distribution and aspect ratios of 15. The future intent of this work is to perform finite element analysis on RVE samples with a range of varied microstructure characteristics to determine the effect on overall composite properties, which will provide new insights on how best to formulate short fibre compounds

Oxygen-controlled recirculating seepage meter reveals extent of nitrogen transformation in discharging coastal groundwater at the aquifer-estuary interface

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Brooks, T. W., Kroeger, K. D., Michael, H. A., & York, J. K. Oxygen-controlled recirculating seepage meter reveals extent of nitrogen transformation in discharging coastal groundwater at the aquifer-estuary interface. Limnology and Oceanography, 66, (2021): 3055-3069, https://doi.org/10.1002/lno.11858.Nutrient loads delivered to estuaries via submarine groundwater discharge (SGD) play an important role in the nitrogen (N) budget and eutrophication status. However, accurate and reliable quantification of the chemical flux across the final decimeters and centimeters at the sediment–estuary interface remains a challenge, because there is significant potential for biogeochemical alteration due to contrasting conditions in the coastal aquifer and surface sediment. Here, a novel, oxygen- and light-regulated ultrasonic seepage meter, and a standard seepage meter, were used to measure SGD and calculate N species fluxes across the sediment–estuary interface. Coupling the measurements to an endmember approach based on subsurface N concentrations and an assumption of conservative transport enabled estimation of the extent of transformation occurring in discharging groundwater within the benthic zone. Biogeochemical transformation within reactive estuarine surface sediment was a dominant driver in modifying the N flux carried upward by SGD, and resulted in a similar percentage of N removal (~ 42–52%) as did transformations occurring deeper within the coastal aquifer salinity mixing zone (~ 42–47%). Seasonal shifts in the relative importance of biogeochemical processes including denitrification, nitrification, dissimilatory nitrate reduction, and assimilation altered the composition of the flux to estuarine surface water, which was dominated by ammonium in June and by nitrate in August, despite the endmember-based observation that fixed N in discharging groundwater was strongly dominated by nitrate. This may have important ramifications for the ecology and management of estuaries, since past N loading estimates have generally assumed conservative transport from the nearshore aquifer to estuary.This work was supported by an award from Delaware Sea Grant (award No. NA100AR4170084 to J.K.Y. and K.D.K.), and by the USGS Coastal and Marine Hazards and Resources Program

The Feasibility of Imaging Myocardial Ischemic/Reperfusion Injury Using \u3csup\u3e99m\u3c/sup\u3eTc-labeled Duramycin in a Porcine Model

When pathologically externalized, phosphatidylethanolamine (PE) is a potential surrogate marker for detecting tissue injuries. 99mTc-labeled duramycin is a peptide-based imaging agent that binds PE with high affinity and specificity. The goal of the current study was to investigate the clearance kinetics of 99mTc-labeled duramycin in a large animal model (normal pigs) and to assess its uptake in the heart using a pig model of myocardial ischemia–reperfusion injury. Methods The clearance and distribution of intravenously injected 99mTc-duramycin were characterized in sham-operated animals (n = 5). In a closed chest model of myocardial ischemia, coronary occlusion was induced by balloon angioplasty (n = 9). 99mTc-duramycin (10–15 mCi) was injected intravenously at 1 hour after reperfusion. SPECT/CT was acquired at 1 and 3 hours after injection. Cardiac tissues were analyzed for changes associated with acute cellular injuries. Autoradiography and gamma counting were used to determine radioactivity uptake. For the remaining animals, 99mTc-tetrafosamin scan was performed on the second day to identify the infarct site. Results Intravenously injected 99mTc-duramycin cleared from circulation predominantly via the renal/urinary tract with an α-phase half-life of 3.6 ± 0.3 minutes and β-phase half-life of 179.9 ± 64.7 minutes. In control animals, the ratios between normal heart and lung were 1.76 ± 0.21, 1.66 ± 0.22, 1.50 ± 0.20 and 1.75 ± 0.31 at 0.5, 1, 2 and 3 hours post-injection, respectively. The ratios between normal heart and liver were 0.88 ± 0.13, 0.80 ± 0.13, 0.82 ± 0.19 and 0.88 ± 0.14. In vivo visualization of focal radioactivity uptake in the ischemic heart was attainable as early as 30 min post-injection. The in vivo ischemic-to-normal uptake ratios were 3.57 ± 0.74 and 3.69 ± 0.91 at 1 and 3 hours post-injection, respectively. Ischemic-to-lung ratios were 4.89 ± 0.85 and 4.93 ± 0.57; and ischemic-to-liver ratios were 2.05 ± 0.30 to 3.23 ± 0.78. The size of 99mTc-duramycin positive myocardium was qualitatively larger than the infarct size delineated by the perfusion defect in 99mTc-tetrafosmin uptake. This was consistent with findings from tissue analysis and autoradiography. Conclusion 99mTc-duramycin was demonstrated, in a large animal model, to have suitable clearance and biodistribution profiles for imaging. The agent has an avid target uptake and a fast background clearance. It is appropriate for imaging myocardial injury induced by ischemia/reperfusion

Coexisting cryptic species of the Litoditis marina complex (Nematoda) show differential resource use and have distinct microbiomes with high intraspecific variability

Differences in resource use or in tolerances to abiotic conditions are often invoked as potential mechanisms underlying the sympatric distribution of cryptic species. Additionally, the microbiome can provide physiological adaptations of the host to environmental conditions. We determined the intra-and interspecific variability of the microbiomes of three cryptic nematode species of the Litoditis marina species complex that co-occur, but show differences in abiotic tolerances. Roche 454 pyrosequencing of the microbial 16S rRNA gene revealed distinct bacterial communities characterized by a substantial diversity (85-513 OTUs) and many rare OTUs. The core microbiome of each species contained only very few OTUs (2-6), and four OTUs were identified as potentially generating tolerance to abiotic conditions. A controlled experiment in which nematodes from two cryptic species (Pm1 and Pm3) were fed with either an E. coli suspension or a bacterial mix was performed, and the 16S rRNA gene was sequenced using the MiSeq technology. OTU richness was 10-fold higher compared to the 454 data set and ranged between 1118 and 7864. This experiment confirmed the existence of species-specific microbiomes, a core microbiome with few OTUs, and high interindividual variability. The offered food source affected the bacterial community and illustrated different feeding behaviour between the cryptic species, with Pm3 exhibiting a higher degree of selective feeding than Pm1. Morphologically similar species belonging to the same feeding guild (bacterivores) can thus have substantial differences in their associated microbiomes and feeding strategy, which in turn may have important ramifications for biodiversity-ecosystem functioning relationships

Review of Major Crop and Animal Arthropod Pests of South Texas

The Lower Rio Grande Valley is an area in Texas that consists of the four southern-most counties. This area contains a diverse range of agriculture and land-use including vegetable, row-crop and livestock production. The year-around cool to hot subtropical climate means that green vegetation is continually present, including many crops. Geographically, it shares an international border, making it a region vulnerable to new invasive species and the re-introduction of pests that have been previously eliminated in the United States. These combined factors lead to an array of arthropod pests that may have serious impacts on the crops, animals, and people in the region. This review focuses on arthropod pests that have historically, currently, or have the potential to significantly impact vegetables, row-crops, livestock, and humans in the LRGV. This is not an all-inclusive re-view but aims to focus on many of the arthropods that have been significant in the last 20 years